An oldie but goodie this time.  Lionel Jeffries’s 1970 adaptation of E Nesbit’s Edwardian children’s novel centres on a well-to-do London family torn apart when the children of the title's father, who works at the Foreign office, is arrested on suspicion of treason.

The film is as English as crumpets, and as warm and cosy as a cup of tea being drunk in front of a log fire in woolly socks.  In order to escape the scandal the mother takes the children to the country, and they end up at "Three Chimneys", a house near the fictional 'Great Northern and Southern Railway' in the Yorkshire dales.

The story then follows the adventures of the Waterbury children, at "Three Chimneys", a house near the fictional 'Great Northern and Southern Railway' in the Yorkshire dales. The three children, Roberta, Phyllis, and Peter, amuse themselves by watching the trains on the nearby railway line and waving to the passengers. They become friendly with Albert Perks, the station porter, and with the Old Gentleman who regularly takes the 9:15 down train. Meanwhile, to earn money to survive during her husband's absence, their mother writes and sells stories to magazines.

After many adventures, including saving the lives of dozens of passengers by alerting a train to a landslide, rescuing a Russian dissident, Mr. Szczepansky, and uniting him with his family, and caring for Jim, the grandson of the Old Gentleman, who is injured whilst participating in a paper chase, Bobbie eventually discovers the truth of her father's absence and appeals to the Old Gentleman for his help.  And the rest as they say, is cinematic history.  (It was remade in 2001, but this version is my favourite.)